Objective To improve the sensitivity of PCR for studying the rifampin resistant gene (rpoB) of M.Leprae from clinical samples.Method After comparing the results of PCR with Q-Solution (PCR Enhancer) and without Q-solution,Nested-PCR was then applied for the detection of rpoB gene.Results Although PCR Enhancer improves the amplification of rpoB gene, the sensitivity of routine PCR is only 45. 2%.The sensitivity of Nested-PCR for detecting mutants in rpoB gene can further increase to 90.5% after selection of optimum parameters.Conclusion The combinaion of PCR Enhancer and Nested-PCR improves the sensitivity and specificity of PCR for detection of rifampin resistant gene of M. Leprae.